Microsoft has recently implemented a policy update for new authentication methods.

my hotmail account just stopped allowing me to sign on. I was directed by microsoft to update my current settings which did not work Any suggestions? failed update procedure was as follows: Microsoft has recently implemented a policy update for new authentication methods. Mozilla Thunderbird does support Modern Authentication and it is recommended that you ensure you switch to use those settings. Any account that you add to Thunderbird will now automatically setup using the proper settings. You have the following options: Option 1: Update Current Settings 1. Change Thunderbird's server settings: Select ≡>Account Settings. In the left pane, select Server Settings for your Outlook.com or Hotmail.com account. ForAuthentication method, select OAuth2 (instead of Normal password). 2. Change Thunderbird's authentication method for sending messages (SMTP): Select ≡ >Account Settings. In the left pane, select Outgoing Server (SMTP). In the right pane, select your Microsoft account and thenEdit…. <image> For Authentication method, select OAuth2 (instead of Normal password). <image> Select OK to save your changes. Option 2: Remove Current Account and Re-Add If you remove your current account from Thunderbird and then re-add it, the proper settings will be detected, and you will just need to sign in to be properly configured with Modern Authentication and the proper server settings. For detailed information and more content, you can refer to this link: Modern Authentication Methods now needed to continue syncing Outlook Email in non-Microsoft email apps - Microsoft Support Hope this help you, please feel free to let me know how it goes. If there is any deviation in my understanding, please forgive me and provide me with more details. I am more than happy to continue to help you. Best Regards, Addie.C - MSFT | Microsoft Community Support Specialist